1. Canadian Institute for Advanced Research, Centre Robert Cedergren, Département de Biochimie, Université de Montréal, Succursale Centre-Ville
Montréal, Québec H3C3J7, Canada; E-mail: herve.philippe@umontreal.ca (H.P.)
2. School of Biological and Chemical Sciences, Queen Mary, University of London
Mile End Road, E1 4NS, London, UK